Although there are more flight travel rules than you could ever fully understand, the basics are fairly simple and boil down to the following notes from the TSA:

3-1-1 Rule – CONSOLIDATE your liquids and gels into a single see-through bag. Liquids and gels must be in containers smaller than 3.4 ounces (100 mililiters), and you can only have ONE bag that is ONE quart sized. Zip lock freezer bags are a good way to go as they are sturdy, cheap, and easy to replace if spills or tears ruin them during travel.